Saturday, December 31, 2011

The wolf is iconic and charismatic. We see him on t-shirts, on posters, and in fantasy novels. Conservationists do battle with ranchers to preserve populations of wolves. The coyote, on the other hand, is neither iconic nor loved. A newcomer to suburbia, he is feared as a suspected predator of cats, small dogs, and even small children. He is rarely seen on t-shirts; his name is not used to designate a rank of Boy Scout.

But now that we have the genetic tools to look at these animals’ genomes, it turns out that many of the populations of coyotes in North America are actually coyote-wolf hybrids, as are many of the populations of wolves. Unable to draw clear lines between these species, biologists have dubbed the populations of hybrids “Canis soup.”

What’s a Canis?

The term “canid soup” has also been used for this mess of wolf, coyote, and even dog genes that we find in some populations of canids. So what does Canis mean, and what is a canid?

These are terms related to the scientific classification of the species in question. Going through the hierarchy, we have Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Canidae (canids), and Genus Canis. Wolves, dogs, jackals, and foxes belong to the family Canidae, but only wolves, dogs, and jackals (not foxes) belong to the genus Canis. We call the wolf-like canids “canines” and the fox-like canids “vulpines.”

As foxes do not interbreed with wolves, dogs, or jackals, what we’re talking about here is correctly Canis soup, or perhaps canine soup, but not canid soup.

Is it Canis or is it soup?

The more you dig into wild canines in North America, the more unclear
it is where any species lines should be drawn. So who makes up our cast
of characters?

Gray wolf
(Image courtesy of Wikipedia)

The first ingredient in Canis soup is the charismatic North American gray wolf or timber wolf, Canis lupus, sometimes known as Canis lupus lupus to differentiate him from the dog and the dingo, who belong to subspecies. The gray wolf is the largest wild canine, at a 79 pound (36 kg) average weight. (Domestic dogs of some breeds, of course, weigh more than that.) His coat coloring can vary from white through blond, brown, grey, and black. He is found in the western parts of North America.

Western coyote
(Image courtesy of Wikipedia)

Next is the Western coyote, Canis latrans. This animal is also known as the American jackal or prairie wolf, suggesting that there has been some confusion about how to distinguish canine species for some time. The Western coyote is a significantly smaller animal than the gray wolf, weighing in closer to 20 pounds (7-14 kg). His coat color is less varied than the gray wolf’s, almost always a grey-brown as you see in the image here.

Eastern wolf
(Image courtesy of Wikipedia)

The range of the Eastern wolf or Algonquin wolf, Canis lycaon, is Ontario, Canada. This wolf is smaller than the gray wolf, and has a distinctive grey-red coat with black hairs along his back. We believe that this wolf was the original North American canine, and that Canis lupus and Canis latrans immigrated over the land bridge from Europe. There’s a lot of debate about the species status of C. lycaon, as many Eastern wolves appear to have significant C. latrans heritage. Some people suggest that the Eastern wolf is in fact a C. lupus/C. latrans hybrid, or, alternately, a subspecies of the gray wolf, C. lupus lycaon.

The Eastern coyote, spreading along the east coast of the United States, is significantly larger than his Western counterpart. He turns out to be a coyote/wolf hybrid, and it has been argued that he should more accurately be called a coywolf. His wolf ancestors seem to be Canis lycaon — but then again, there is debate about whether C. lycaon is really different from C. lupus at all.

The red wolf or Southeastern wolf is subject to truly intense debate about species status. Is he his own species, Canis rufus? A subset of the gray wolf, Canis lupus rufus? Or a population of Eastern wolf, Canis lycaon? He has a beautiful red coat, and is smaller in size than the gray wolf. His range was historically the southeastern U.S., but he went extinct in the wild by 1980. A founder population of 19 animals survived in captivity, and a reintroduction project in North Carolina was begun in 1987. Here the red wolf is today enthusiastically interbreeding with coyotes, leaving conservationists to wonder what they are conserving.

The three species of wild canines in North America today, then, are Canis lupus, Canis latrans, and Canis lycaon. But we really have just two soup ingredients, wolf and coyote. There are pure wolves (Canis lupus) and there are pure coyotes (Canis latrans),
and there are populations that are mixtures of more or less wolf and
more or less coyote (Eastern wolves, Eastern coyotes, and red wolves).
There appears to be some dog mixed in there, too. You can think of gray
wolf and Western coyote as ingredients, and everything else as soup.

Coyote flavor versus wolf flavor

The 2011 paper “A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids” analyzed the various soup flavors out there and presented their findings in some easy-to-understand charts (below). Here, the different colors represent different amounts of each ingredient. The first chart describes the Eastern wolf, here referred to as the Algonquin wolf, which is mostly gray wolf (green) and joint wolf/coyote (yellow), but also has significant coyote (red). The second chart describes the red wolf; at a glance, it is obvious that the red wolf has a much larger percentage of coyote genes (again, red in this chart). These charts both use τ to denote the number of generations since the most recent admixture with another species.

Two recipes for wolf flavored Canis soup
(vonHoldt, 2011)

The two coyote recipes pictured below describe two subpopulations of what I have described as the Eastern coyote; this particular paper considers them split into Northeastern and Southeastern coyotes. At a glance, these populations are mainly pure coyote (red), with big dashes of mixed coyote/wolf (yellow), and small but notable amounts of our friend the dog (dark blue, light blue, and pink).

Two recipes for coyote flavored Canis soup
(vonHoldt, 2011)

Wild canine populations challenge us to let go of our obsessive need to categorize. Instead of slotting a canine population into a single species category, we might instead think of it as existing on a spectrum from “wolf-like” to “coyote-like.” A strongly wolf-like canid would be larger, sixty to ninety pounds. He would require a larger range, and would be a deerivore, subsisting off of larger game. He is likely to be a shyer animal, found only in more rural or wild areas. Conversely, a strongly coyote-like canid would be much smaller, fifteen to thirty pounds, with a smaller range. He might eat deer as well as rabbits and et cetera (probably a lot of et cetera, as coyotes are more willing to scrounge than wolves are). He would be more likely to be found in suburban areas, with a greater tolerance for human proximity. A given population of canines might fall anywhere on the spectrum between the two. The fact that a spectrum actually exists is beautifully demonstrated by the Eastern coyote, who has mixed coyote/wolf ancestry, is mid-sized between coyote and wolf, and has a mid-sized range.

What’s your preferred flavor?

Does the intermixture of various ingredients in the formation of soupy populations matter as more than a gee-whiz story? To some people, the answer is very much yes. The conservationists who are committing significant resources to the preservation of the red wolf don’t want to see the wolves that they reintroduce interbreed with coyotes. If the reintroduced wolf population blends into a coyote population, then are these resources actually being spent just to support a bunch of coyotes (who have been doing fine on their own)? At the same time, evidence shows that the founder population of 19 red wolves was already significantly coyotified, and we’re not sure how long it’s been since there have been any pure Canis rufus specimens in North America.

It is, of course, possible to think about the problem without asking for genetics to provide the complete answer for us. The red wolf is a red wolf, a beautiful, iconic animal that has lived in the southeastern United States throughout living memory. We know what the red wolf looks like (and that hasn’t been changing much, no matter what is happening to his genes). We also know that he is important in a particular environmental niche, and that hasn’t been changing much either.

Practically, the mixture of coyote genes into fragile wolf populations may be a good thing. Because coyotes are better at living on smaller ranges and in closer proximity to humans than wolves are, they are better adapted to the realities of North America today. As their genes mix into wolf populations, these populations become demonstrably more robust, more able to tolerate human presence, and able to survive on smaller ranges. It is possible, in fact, that coyote genes are exactly what are eventually going to allow a red wolf population to flourish without human assistance.

Conclusions, if we can make any

Does it matter that some of
what we think of as wolves have coyote genes? I think the answer comes down to a cultural perception of the wolf as a romantic and charismatic creature, and of the coyote as a pest. Perhaps any mixture of the two is perceived as diminishing the wolf. A friend of mine once made this analogy: if you have an entire bottle of fine wine, and you pour just a teaspoon of sewage into it, now you have a bottle of sewage. Does any amount of coyote, no matter how miniscule, make the wolf impure, and less worth conserving than it was?

As a culture, I hope we can come to appreciate the strengths that the coyote brings to Canis soup, in his ability to coexist with humans in the modern world. He may be what saves populations of charismatic wolves from permanent loss. As we look at populations of canines in North America, we should learn to say that one is more coyote-like and another more wolf-like, on a spectrum from one flavor of soup to another, and appreciate the benefits of both.

Canis soup has been used before as an example of the blurriness of some species lines and the inadequacy of many existing definitions of a species, but it also provides some interesting insights into the fluidity of canid morphology and behavioral characteristics. How did something as large and wild as a wolf become something as variably-sized and tame as a dog? Moreover, how did this change happen (presumably) without a carefully planned breeding program? Why is it so easy to breed types of dogs with such different behavioral and physical characteristics, especially compared to the much more limited variety of breeds of cat, horse, or cow? The canine genome clearly has the capacity for expression across a startlingly wide array of phenotypes. The evidence of this variety has always been right before our eyes, but we are just beginning to understand its implications.

Wednesday, December 21, 2011

I recently finished Control Unleashed: Creating a focused and confident dog, by Leslie McDevitt. This book is designed for people training dogs in agility who are having issues with their dogs’ ability to focus, so you might imagine that the book isn’t useful to people with fearful dogs like mine. But it turns out, unsurprisingly, that if your dog is having issues focusing, he may well actually be nervous about something in his environment, such as strange people or other dogs. This book is full of exercises for helping your dog be more comfortable and relaxed, whatever his reason for being distractable. It was incredibly helpful to me in thinking through exercises for my shy dog Jenny, to help her learn to trust the world a little more. Even if you don’t do agility with your dog, this book may be helpful in making you a better trainer. It includes many examples of specific training exercises to try, and stories about situations in which they were particularly helpful. It was also an enjoyable enough read that I got through it while working long hours on some difficult rotations — I looked forward to finding ten minutes to read it before bed. I recommend this book to everyone who has has basic understanding of positive training and learning theory, and wants to learn more.

Sunday, December 4, 2011

Some days it seems like none of your patients will eat. I asked the intern at the wildlife clinic where I was doing a two week rotation what his advice was for convincing the tiny screech owl (214 grams of cute) to actually ingest food on her own. We had tube fed her; this worked, but you don’t really want to have to do it every day, and she really doesn’t want you to do it every day. We had force-fed her mouse bits with tongs, which was even worse. The intern suggested peeling the skin off of baby mice “so she can see the meat.“

Awesome.

In vet school, you get a little inured to gross things. I cut up mice for raptors every day on this rotation without getting squeamish. But I found peeling the skin off of two day old mice (thankfully already dead) to be a bit much. The intern was a little bewildered by my reaction. Anyways, it didn’t work.

The next day I went to a different vet for advice. “Sometimes,” she said, “they like to have the mice split open and the liver displayed... You can leave the skin on.” I did this. I was artistic about it. HERE ARE THE LIVERS. PLEASE EAT THEM.

And that night, she ate.

My next problem patients were two barred owls who had recently been transported a fairly long distance, which we were examining before they were placed into permanent captivity, as they were not releasable. These guys really didn't want to eat. I laid the mice out enticingly next to a branch on the ground. I split them open and DISPLAYED THE LIVERS. No.

The intern said, “They don’t want to come off their perch. They’re scared. Put the mice on the perch.” Easier said than done (he said it, I did it). One of the owls inevitably reacted to my entry into the pen with OH HOLY CRAP I AM GOING TO DIE, flying back and forth at high speeds. It wasn’t a very big pen. I covered my head with my arms and crept at a snail’s pace towards the perch. Veeeeery slowly I balanced the mice on the perch. And crept away again. That night, the owls ate.

The next day, as I was artistically displaying peeled mouse haunch for an Eastern box turtle (the mealworms weren’t working as they would just escape into his cage and set up shop there) I thought to myself: how did this become my life?

Saturday, November 26, 2011

Today I heard this sad story third-hand: as a baby is crawling away from Grandma’s dog, who has always been fine with him before, the dog without any warning pounces on the baby and bites him. The baby loses part of an ear and has deep wounds on his face. The dog is euthanized. The parents were there to supervise, but it all happened too fast to prevent. What went wrong?

The first thing I want to say is that at the point that a dog bites a child (or any human) this badly, I agree that the dog must be euthanized. He is not safe. For this reason, it’s really important to figure out how to keep this situation from happening in the first place, for the sake of the baby and the dog.

What was going on in that dog’s head? We can’t know for sure, but it sounds to me as though the dog was treating the baby like prey. He pounced when the baby was moving away from him, and he bit to injure. If he had been trying to play with the baby, he might have bitten hard enough to bruise, but dogs have excellent control of their teeth, and a bite bad enough to remove part of an ear was probably intentional. The fact that the baby was moving away from him at the time is supportive evidence — the sight of something small and helpless, which makes high-pitched noises and moves erratically, running away from him may have triggered him to act.

Do dogs really act like predators around babies, even if they know them? Some dogs, not all. I would be particularly suspicious of dogs with high prey drives — dogs who are obsessive about chasing small animals outside. They may learn to like small animals who are part of the family, like cats, but with dogs like this, I would be very careful with my introductions. In the case of a human infant, I wouldn’t leave the baby on the floor with the dog loose in the same room unless I really, really trusted the dog. I live with four good dogs who get along just fine with cats, but there is only one of them that I would trust with a baby on the floor. The price is just too high if you make a mistake.

How can you prevent such a situation, since the dog gave no warning signs? I was not there, but I can almost guarantee you that the dog did give warning signs; his owner was just not trained to read and understand them. The dog probably did subtle things like stare at the baby a little too long or sniff it a little too aggressively — things that wouldn’t make the average dog owner think twice, but would make the average dog trainer extra cautious.

So what do you do if you’re expecting a baby and you have a dog? Or if you are a grandmother and want your grandchild and your dog to get along? The safest and easiest answer is to not let the dog and child interact until you know you can trust them together. Put them together for short periods of time only, while you are holding the child, and observe the dog closely. Don’t leave them on the floor together until you are confident that the dog will ignore the child and that the dog shows no stress, fear, or predatory behaviors around the child. If you don’t think you can read the dog well enough to tell, hire a dog trainer to evaluate your dog. A dog trainer can help guess what problems your dog might have around a child, tell you specific signs to look for, be a resource to ask questions, give you tips on how to manage them together. To find a certified dog trainer in your area, search on the Association of Pet Dog Trainers site.

Dogs and kids can get along great, if they are introduced carefully, and when the kid is old enough. But the consequences of a bad relationship between the two are so serious that it is very important to take those introductions seriously, and to make sure you’re seeing things from your dog’s point of view before you assume everything’s okay.

Sunday, November 20, 2011

The skinny little tree was only about 30 feet tall and growing in the middle of a swamp. Recent flooding had surrounded it with water several feet deep. And yet somehow an orange cat had managed to climb it. He was perched precariously: when I first saw him, he was jammed into the fork of two branches, and his every movement made the little tree bend. I was riding with an animal rescue service, and we had been called out to get the cat out of the tree. It was supposed to be a simple job of using climbing gear to get up the tree; the rescue driver was trained to do jobs like this. But this tree was never going to bear her weight. It could barely hold the cat. Even getting to the tree was going to involve wading through waist-deep water in the chilly November weather.

The cat was glad to see us. He made eye contact and meowed, clearly asking for help. But it was not immediately clear how to help him. We talked about our options, and eventually decided that we were going to have to call back to the shelter for assistance. The rescue driver called her boss, but initially failed to convince him that she couldn’t just climb the tree. She eventually had to photograph the situation on her phone and send him that as proof that the tree couldn’t support a ladder, and that trying would just knock the cat off so that he would fall 30 feet into the cold water.

As we watched and talked about what to do, took photos and made phone calls, the cat eventually stopped talking to us. I think he gave up on us. A few minutes later, he decided to change positions. I think his legs were getting tired of holding him up. After all, we had no idea how long he had been up there; a good samaritan had phoned about him about an hour previously, but the road we were standing on was small and rarely used, so he could have been there unnoticed for hours. I also think he was trying to assess his situation, see if he could take matters into his own hands and find his own way down, since we were clearly useless.

As he moved around on the little tree, it bent terrifyingly. Unable to help ourselves, the rescue driver and I yelled “No, stay still!” up at the cat. This had about as much effect as you’d expect. But he managed not to fall. Over the next thirty minutes, waiting for help to arrive, we watched as he periodically moved around and tried to find a way down. We became worried enough about him that the driver put on her dry-suit and made her way down to the water so that she could fish him out if he fell.

Finally, as the light was failing, our help arrived, in the form of the driver’s boss who had driven down from Boston. Now things started to move quickly. As the cat watched with trepidation, the driver got into the water (in her dry-suit) with a big net; I hovered with another big net; and the driver’s boss attached ropes to the little tree. He pulled, and the tree bent towards the roadway where we stood. The cat braced himself, then, when he was only about ten feet off the ground, jumped. I swung with the net and missed. We watched as the cat ran at top speed away from us down the long road and disappeared into the night.

Thursday, November 10, 2011

Yesterday I spent the day on a spay/neuter trailer. The shelter which owns the trailer sends it out to low-income areas to spay and neuter a large number of cats and dogs at low cost. Yesterday was a slow day; we spayed and neutered sixteen cats. Well, the vet spayed seven and neutered three; I spayed one and neutered three. Meanwhile, she explained high volume spay/neuter techniques to me.

The key to high volume spay/neuter is, obviously, speed. She can spay a cat in seven minutes. It takes me about thirty; a general practitioner who has more experience than I do, but isn’t as obsessed with speed, might take ten or twelve. This is what I learned:

Keep your surgical field (the animal!) clear. Take the time to replace your instruments on your instrument tray when you are not using them, so that you have less visual clutter.

Always know where each surgical instrument belongs. Don’t leave them in a pile or even a random row on your tray. Have an order for them — any order, so long as you are familiar with it and can reach for a particular instrument and know right where it will be.

Don’t waste movements. If you’re reaching to the right to grab a new instrument, don’t twist all the way over to face the tray; just reach your right hand over.

Don’t get tangled up in your instruments. Be willing to take a second to switch hands if you have yourself in an awkward position.

As you’re working on one step, have your next step in your mind. What instrument will you be reaching for next?

Friday, November 4, 2011

Sadie was a rambunctious young shelter dog whom I had been assigned to exercise and train. We were working in an auditorium, the best space the shelter had for exercising dogs indoors. Like most of the dogs I worked with in there, Sadie had some trouble with the smooth floors; every time she ran to catch a ball she would slide and slam into the wall. Because she was basically an oversized puppy, this didn’t faze her. We were having a great time, working on her retrieving skills, practicing “drop it” (at that point, just a swap of the ball for some treats).

Then Sadie saw some dogs playing outside through the big glass doors on one side of the auditorium. Sadie was already diagnosed as dog aggressive, which was part of why she was inside playing alone with me. The mood of the session changed immediately. Sadie ran at the glass doors, barking and racing back and forth. I tried to interpose my body between her and the doors, to back her up and get her attention back on me, but it was like I wasn’t there. I wanted to put her leash on to back her away, but I was worried that grabbing her collar would cause her to turn and bite me.

I made Sadie’s leash into a loop and lassoed her with it, then backed her away from the glass doors. She still wasn’t focusing on me, but neither was she turning to bite me as we backed to the far end of the room, where I sat down on a low stage and kept her on leash. She had her back to me, focusing on the doors. She couldn’t see the dogs any more, but she could hear their deep hound barks, and she really wanted to get at them.

Sadie had worked with a clicker already, so I pulled out my clicker and started to click her for any movement away from the door. Step back towards me: click, handful of treats. Quick look over her shoulder when I made kissing noises at her: click, handful of treats. I kept up a very high rate of reinforcement to keep her interest, so she was essentially being fed a steady stream of pieces of hot dog. Gradually her body language changed, so that she was not arrow-straight pointing at the door. She became looser, more relaxed. She turned towards me, looked at me (treat, treat, treat). And then finally she was lying down next to me, leaning into me, enjoying having her sides rubbed. When the dogs barked, she looked over towards the doors briefly, then back at me. She was with me again.

Friday, September 30, 2011

Day 8 was not like the other days. My rotation-mate Delilah and I signed up to spend the day assisting with embryo collection at a farm that works with my school to preserve heritage breeds. The farm acquires (usually on loan) individuals from heritage breeds of sheep, cows, and goats. They superovulate and breed the females, then collect the embryos and cryogenically store them. Del and I kept asking what the plans were for the embryos. No plans! We are just storing them in case they are needed some day when these breeds are extinct.

The facility was beyond lovely, a 1920s folly farm that looked like a crazy cross between a medieval castle and a Mexican mansion. Biosecurity was a big concern there, so we had to cross a little bridge with a foot wash on the way in, and multiple signs about the premises said things like “This is private property. Please go away immediately.” The grounds were so immaculately clean that it was hard to believe there were animals there, but there were, beautifully cared for (with lots of pasture!). The farm was restored and updated, so you would for example pass through a stone archway into a modern cryogenic storage facility. Also, it had the cleanest bathroom I had encountered on a farm yet, but then again, that is not saying much. Most farms have bathrooms that rival the worst truckstop bathrooms, so that the vets who drive the trucks will say things like “hang on, we’re passing by a gas station in less than an hour” when you ask about facilities.

Del and I traded off assisting on surgeries and running anesthesia for three ewes. We premedicated, intubated, and maintained each ewe under anesthesia on gas. Then we helped Dr. Thery go in laparoscopically to make sure she had in fact successfully been superovulated. Ideally the ovary would look like a bunch of grapes. We would count the post-ovulatory structures on each ovary. Then we would laparasopically find and grasp the uterus, and pull it out of a small incision. Once it was exteriorized, we flushed it to get all the embryos out of it. The embryos were carried over to the lab, and we watched on video as they were identified, counted, and graded (the more vs less viable ones selected out). We closed up the ewes and recovered them. Each ewe would be kept for two surgeries, then returned to her owner.

It was a lovely day, and of course the surgery experience was a fun bonus. Del and I had some interesting conversations about whether this effort to preserve heritage breeds was worth the investment. Whether or not it is, it was a beautiful facility, and nice to see how a farm can be run when money is essentially not a factor.

Sunday, September 25, 2011

Day 7. Just me and Dr. Gray (my favorite doctor to ride with). He blasted out of the clinic at high speed, announcing that we were extremely late and that we were going to check on a herd which had a problem with cystic ovaries. He tossed me a copy of Merck’s Veterinary Manual and said, “Let’s get smart about cystic ovaries.”

He and I at least knew what cystic ovaries are, but I am betting you do not. What you want an ovary to do is to grow a bunch of follicles, and then have one follicle decide it is the queen follicle and ovulate an egg. You probably know what happens from there. If this process is stymied at some point so that the follicle just hangs out and doesn’t develop, but becomes a bump on the ovary full of liquid, it is a cyst. The cow may recover from this and return to a normal reproductive cycle, or her system may become confused by the particular mix of hormones circulating and get hung up. The a veterinarian has to figure out what is going on. The most common explanation is that the cows are not eating well enough, so we came prepared to look into that.

We pulled up at a lovely little farm. This was a hobby farm in the sense that the owner had income from elsewhere, but a real farm in the sense that he was trying to make a profit on selling milk. He actually had a farm store where you could buy milk from that farm (unheard of!) and ice cream made from the milk (even better!). I purchased both, since the cows were out on grass, which made me happy. (The milk later spilled in Dr. Gray’s truck and went bad so that he became cranky with me, but that is a different story.)

Herd check. Why did the cows have cysts? The usual veterinarian for the herd was present; we had been called out as consultants basically because we had an ultrasound machine to help us better see what was going on inside the cows. We checked cow after cow. Some follicles (excellent), some post ovulation structures (also excellent). No cysts. It turned out that what had appeared to be cysts were actually normal structures. The cows were in fact somewhat skinny, so we also did some education about how to body condition score a cow. This was a learning experience for me; it is more complicated than with a dog, involving a flow chart. We also gave advice about how to synchronize the cows so that the farmer would know when to breed them. Without a solid synchronization program (or a bull, which most people find dangerous to keep around), you just have to watch the cows to see when they might be in heat. They are in heat for such a short period of time, less than a day, that it is very easy to miss. Best to know ahead of time when it’s going to happen.

We got back in the truck. I ate my ice cream sandwich for lunch. It was a good lunch.

The next farm was very different. Instead of the welcoming committee of three people who had received us at the first farm, we were left to find the sick cows on our own. Eventually one of the employees handed us a list of numbers: three cows with possible twisted stomachs (displaced abomasums) and one that might have a dead calf inside her. Usually farmers catch the cows up for us and have them in headlocks, but not here. Go find them!

The sick pen had dozens of cows in it. Dr. Gray and I wandered through until we found our girls, then chased them into a small side area where we could put them into the single head lock one by one. The cow with the presumed dead calf was pretty sick, so Dr. Gray dealt with her while I checked TPRs (temperature, pulse, respiration) and gave physical exams to the other three. I couldn’t see him, as he was behind a barrier from me, so I was on my own.

First cow: already in the head lock thanks to Dr. Gray. Normal TPR. No pings (the sound they make when you thwack your finger against their belly and they have a twisted something or other inside there). Looked bright and alert and not dehydrated. I relayed this to Dr. Gray, he came over and double checked, said we would just recommend some oral fluids, and I should move on to the next cow.

Second cow: obviously not in the head lock. I released the first cow and tried to get the second cow in. They will move away from you, so you can basically chase them into where you want, but she would not actually put her head in the lock. They weigh a lot more than you; sometimes you can shove on the back end and they will be nice about it, but there was no way this girl was cutting me a break. It was a little embarrassing, but I did my TPR while she was loose.

This time Dr. Gray came back with blood on his arm up to his shoulder, looking stressed. He checked over the cow (who he also failed to get into the head lock), gave her a rectal exam (this was all with a bare arm — iew), gave her the same diagnosis as the first cow, and went back to what he was doing. I walked back to watch as he shot the sick cow with the dead calf inside her in the head with a captive bolt gun, standard euthanasia technique on farm for a cow who cannot make it on to a truck to be shipped to slaughter.

Dr. Gray explained that the cow had had a dead calf in her for several days, and had a large rip in her uterus, which she could not recover from. I will save you from some of the gorier details. He was clearly somewhat bothered by the fact that the calf had died at least four days before and she had not gotten medical attention before then. “To be fair,” he said, “the calf wasn’t in the birth canal so she probably didn’t show any signs of labor for them to notice.” I said, “Is this maybe a case where on a smaller farm, someone would have realized something was going on with the cow which was supposed to have freshened a few days ago?” He allowed as to how that was probably the case.

Then we checked out the fourth cow, the one which was also supposed to have a displaced abomasum. Amusingly, this cow stuck her head into the head lock enthusiastically. We were running late, so Dr. Gray did this exam himself, and did find a problem. He is a fan of a toggle procedure to fix displaced abomasums, so that is what we did, instead of the surgical procedure I had seen previously. With the help of a farm hand, we sedated the cow, put ropes around her, pulled her over on her side, and rolled her on to her back. Once she was on her back, her stomach floated into the correct place. Dr. Gray put two pins into her belly, puncturing through the skin and into the stomach. He used the pins to secure the stomach in place. The cow was allowed to stand up and was good to go (with dextrose, steroids, oral fluids, oral calcium, and B vitamins to help her out).

Then we washed off in a bucket. There was a lot of scrubbing to be done. And that was day seven.

The nice thing about having weekends free on your ambulatory rotation is that you can do the things normal people do with their weekends, like go to incredibly geeky dog training seminars about the details of learning theory. I went to a seminar on improving the cues you give your dog with the brilliant Kathy Sdao. Some of her main points, below.

A command is something you give with the expectation of making the animal obey. A cue is something you give to say “you know that behavior that you have learned is a really good thing to do, because you often get paid to do it? Now would be a great time to do it!”

Oh, for those of you who aren’t dog training geeks, I should back up. “Getting paid” is dog training lingo for the idea that dogs don’t work for us just because they love us. Do you do work because you love your boss? Dogs get paid with food, praise, life rewards (getting a ball thrown), etc.

You can’t control a behavior. You can only control what happens before and after a behavior, and therefore the animal’s expectation for cues that predict a good or bad time to perform the behavior, and consequences of the behavior.

You certainly can use cues which are difficult for your dog to distinguish, like down and out, which have the same internal vowel sounds and are very similar to the ear if you don’t have human-level language skills. However, why would you? Choose words that make things easy for your dog by being easy to distinguish from each other. Your dog is the one who is struggling to understand language, something his species does not excel at.

We know it, but it’s worth repeating: a dog doesn’t refuse to perform a behavior for spite. That’s only something humans do. A dog who doesn’t respond to a command or cue does so for only one of two reasons: a) he doesn’t understand what is being asked of him, or b) he doesn’t feel it is worth his while (he is not being paid sufficiently).

We think of cues as verbal or gestural. Of course, dogs are more comfortable with gestural cues in general. (One participant found that her dog completely ignored a verbal cue which she had always given paired with a gesture.) You don’t have to make gestures only with your hands! Some people with small dogs find that the dogs respond very well to foot gestures, which are closer to their eye level.

Cues that we give without meaning to include eye movements, where our attention is, body language (the classic story of the dog refusing to lie down unless the owner bends forward, because that may not be the cue the owner taught, but it is the cue the dog learned). Tone of voice. Time of day. Antecedents like picking up your keys. My dogs have learned that “okay,” spoken while I am on the computer, means I have decided to get up and get myself off the keyboard, even though it is something I say unconsciously to myself and not intentionally to them.

Dogs live in a sea of information coming from us. Sometimes it is hard for them to pick out the cue we want to give. You think you are just raising your hand to indicate sit, but the dog is taking in tone of voice, where you are looking, if you are bending forward, what your other hand is doing, the position of your feet. It isn’t obvious to the dog that the hand (or word) is what he is supposed to be paying attention to.

Kathy gave two examples to illustrate that point. The first: you know the feeling you get when you are tuning a radio and you can’t quite get the station, and have to listen to it through static? Dogs live in that world all the time.

For those who know the invisible gorilla illusion — if you don’t know to look for something, you may not see it. If the dog is paying attention to how far forward you are leaning, he may not even hear the word you are saying to him. After all, words come out of your mouth all the time, and he usually doesn’t understand them. Why should he pay attention to this one and assume it has some importance? Why should his brain even filter is so that he hears it at all?

We played a fun game with the participating dogs called “Prove It.” The handler asserts something like “my cue for sit is the word ‘sit.’“ The challenger says, “Yeah? What if you say it with your eyes closed? With your hand over your mouth? Looking at the ceiling? Whispering? Standing on a chair? Will your dog still do it then?” I worked with a handler whose dog did standard commands flawlessly, promptly, and enthusiastically. When her handler told her to sit while looking at the ceiling, the dog stared at her hopefully, trying to figure out what she was supposed to do. (During this game, we took lots of breaks to give the dogs easy tasks and reward them.)

Fun day learning about how to communicate with your dog, and gave me good insights into my own training methods. Kathy Sdao is an excellent teacher. If you are a beginning trainer, her classes may seem a little arcane to you, but I highly recommend her if you are a learning theory geek, or someone who teaches other people to train dogs.

Monday, September 19, 2011

Day 6. Another herd check. It’s becoming routine. To be fair, I tend to end up riding with the clinicians who do herd checks, because I want to spend these three weeks working with cows. I have so far avoided riding with the clinician who specializes in horses, because equine medicine bores me silly. I like horses, just not horse medicine. And I really like cows, who are endlessly sweet and amusing, and I like herd health, or population medicine. Put me on a farm with a few sick cows and I am perfectly happy to spend hours talking about what is wrong with farm management which is causing these cows to get sick. Ask me to actually do procedures on an individual cow and I start wondering when we are moving on to the next farm.

So. Day 6, herd check. After all the rectal palpations there is inevitably the one or two sick cows to check on, or in this case, three. One was six weeks fresh (gave birth six weeks ago). You always, always ask how fresh a cow is, or if she is not particularly fresh, how many days in milk (how long she has been giving milk, i.e., how many days ago she gave birth — I have been told things like “this cow is 510 days in milk”). They get different diseases depending on where they are in the whole calf-milk-breeding-no milk-calf cycle. This one, being six weeks fresh, should have been past any problems with her uterus recovering from labor, but was not. Which was why we were being asked to look at her. We recommended infusing her uterus with dilute iodine to get rid of the infection.

The next cow had aborted two days previously. She still had bits of placenta hanging out. Normally retained placentas clear themselves within a day or two, but this one was hanging in there a little long, especially for having quite so many pieces still stuck in. My syllabus says it is “controversial” to “manually clean” the uterus of retained placenta (i.e., go in and pull the bits out by hand). It is usually better to let nature take care of this, as upsetting as it is to see cows walking around with pink stuff dangling out of their private parts (what small animal owners inevitably refer to as “down there” and what farmers will refreshingly refer to as “vaginas”). In this case, we manually cleaned. Well, the vet cleaned, and I watched. Good times.

Sick cow #3 had some hair loss on her heels and at the head of her tail. The clinician took one look and pronounced her as having mange. We applied a parasiticide: the vet handed me a big bottle and told me to pour it along the cow’s top line. The stuff was bright purple. Now the cow was bright purple. More fun than cleaning placentas.

Farm two. A big farm, but a well run one. They were having a diarrhea problem with many of their calves (“calf scours”). We drew blood on some four day old calves to check to see if they had gotten enough antibodies from their dams in the colostrum (milk full of antibodies) that they drank in their first few hours of life. (Back at the clinic, the answer was that two of them were fine, and two of them were borderline for not having enough antibodies.) This was a great example of a herd health problem. Why were these calves getting sick? It seemed to be some management problem, but where exactly was the farm going wrong? If the calves weren’t getting enough colostrum, why not? The guy in charge of calf management spent a long time talking to the vet to try to figure it out. So far, we still have no answer. I hope they manage to find one.

Saturday, September 17, 2011

Day 5. I was refreshed after a weekend of sleeping 13 hours a night (still catching up after my exhausting small animal surgery rotation the previous month). I signed up to ride with Dr. Gray and my classmates Will and Anna.

Farm one. A largish farm for a family farm, but run by people who clearly really cared about their cows, a mom and daughter team. Anna performed a castration; Dr. Gray said I could show her how since I had done one before (making me an expert, clearly). There was a long discussion about whether to use lidocaine (a painkiller) or not, as there always is when calf castration is discussed. Since this is something I’ve thought about a lot, I was able to present the usual pro and con arguments to my rotation mates. We used lidocaine. The calf was a lot bigger than the one I had done before. My advice: do them younger. The restraint is a lot easier.

Then we did the usual herd check. One cow had had a forced extraction recently, a difficult birth ending in having the baby pulled out of her using chains. Dr. Gray did a vaginal exam, which is more uncomfortable for the cow than a rectal exam, such that students are not allowed to follow after and do their own exam. She had multiple internal lacerations, so Dr. Gray recommended antibiotics and pain killers. This was one of those sticky situations where pain killers weren’t absolutely necessary, just indicated for the cow’s comfort. He thought the farmer wouldn’t want to give them and considered not even suggesting them, but in the end did suggest them (“if you wanted to give some banamine, it wouldn’t be wrong”) and the farmer promptly agreed. I had thought she would, since she seemed to really care about her cows. Veterinarians, it is not wrong to just suggest the best care, even if you think your client will say no! You just have to find a way to do it in a way that won’t make your client feel uncomfortable if they do feel they can’t afford it.

Overall, I mostly liked how these cows were kept; the health of the cows was clearly a high priority on this farm. I am still not happy that the industry standard keeps cows on slippery concrete where they are bound to develop foot problems (10% of a herd is expected to be lame on any given day), walking in manure so that they are caked with it up their legs, and not getting to eat the grass that they evolved to eat.

Second farm of the day: we preg checked (pregnancy checked, rectally) about 100 cows. PHEW. Luckily there were three of us. As the herd check started winding to a close, Dr. Gray put Will and me on the task of giving the cows the injections that they needed. When a cow was preg checked and found to be open (not pregnant), with structures on her ovary to indicate that she had recently ovulated, she got an L written on her side in orange chalk. When she was pregnant she got a P. Otherwise she got nothing. I injected all the P cows with a multiple vaccine. Early pregnancy is a good time to vaccinate so that the mom will pass on the antibodies to the baby in her colostrum after birth. Will injected the L cows with Lutalyse. This is a hormone (prostaglandin F 2α) which causes them to reset their estrual cycle so that they will ovulate in the next three days and can be bred again. In general the female vet students avoid handling Lutalyse, because if it gets in our system we get very bad cramps. I was glad to have Will there to give those injections.

Monday, September 12, 2011

Day 4. Friday! I was hugely looking forward to having an actual weekend off, with no responsibilities in the hospital for the first time in 5 weeks.

I was one of the first students in to the clinic. Dr. Cole caught me and my classmate Will as I was coming in and told us that a client had just pulled in. She was bringing her extremely elderly and sick dog in to the clinic for euthanasia. The clinic technically doesn’t handle small animals at all, but Dr. Cole was willing to help out the client in this case. We euthanized the dog in the back of the truck, lying comfortably on his blanket. Will and Dr. Cole handled the actual euthanasia, while I talked to the owner about her dog, what he was like.

I rode with Dr. Thery that day. We went out to a small farm which produces artisanal raw cheese for sale in New York city and directly to restaurants in the area. I loved this farm. The cows were all out on grass all summer. The barn was old but very well maintained, not overly dirty. The cows were extremely friendly; even the calves were not head shy at all. We did a herd check, popped an abscess on a cow’s flank, and vaccinated and TB tested a mess of heifers (about to be sold across state lines) and calves.

I kept ducking out of doing the actual medicine to go talk to the farmer about how she makes grass feeding work. Grass feeding is the norm for beef cattle before they go into feedlots, but for dairy cows, conventional wisdom is that they have to be handled too much to make it work. What a pain to have to round up all your cows twice a day for milking! But the farmer shrugged that off. The cows want to be milked, because their udders get uncomfortably full. They come back in to the barn voluntarily. Once they know the routine, it’s no problem.

I wish all farms could be like this one. I know that’s a pipe dream, but I still really want to find a way to support farms like this one, to make it just a little easier for farmers to do what I consider to be the right thing by their animals.

Saturday, September 10, 2011

Day 3. I signed up to ride with Dr. Cripi, just him and me. I was hopeful that I would get to do more hands on stuff when I was not competing with other students for opportunities.

I expected to get right in the truck and head out, but Dr. Cripi said that a cow was being brought to us this morning. Some farms are so far outside the clinic’s usual area that they are only worth visiting if there is some other work in the same region. These farms can be our clients, but have to let us schedule our visits to groups of them on the same day. When they have emergencies, they have to bring their animals to us. This was why the cow was coming to us now.

She got off the truck nicely and we put her in the stocks so that she was restrained and could easily be examined. Dr. Cripi noted that her eyes were sunken, indicating dehydration. Some other students were standing around as well, and we all got to examine her. A large part of examining a cow is trying to identify problems with its complicated GI system. If part of the GI is displaced to somewhere it shouldn’t be (a fairly common problem, especially in cows that are fed too little roughage in their diets, e.g., are not out on pasture or fed mostly hay) then that part of the GI will start filling up with gas. You can “ping” the cow to hear this. You snap a finger hard against her side while listening with your stethoscope. This was the first ping I had ever heard, as I had never before examined a cow with a displacement. It sounded like a basketball bouncing on a metal floor. I referred to the ping as “gorgeous,” which amused the farmer no end.

This cow had an RDA, or right displaced abomasum. This means that the cow’s true stomach, or abomasum, had floated up on the right side of the cow. (Normal location: right side, but a lot more ventral, e.g., closer to the ground). We performed standing surgery on the cow to fix the problem. We did not sedate her, as she was so sick that Dr. Cripi thought sedation would make her lie down, which would make the surgery much more difficult. We did give her a local block in the area where we would be cutting. Then she was shaved and prepped (aseptically scrubbed) over her right side.

First we scrubbed in. This was hilariously different from scrubbing in to surgery in the small animal hospital, which I had done a lot of on my surgery rotation over the previous month. A cow holding area is going to be inherently dirty. We scrubbed our arms off with iodine and put on long surgical gloves (they have to go up to your shoulder, because you’re going to be reaching deep inside a big animal), then normal sterile gloves on top of that.

Then Dr. Cripi made a maybe 5 inch incision in the cow’s side. She didn’t seem to notice; hurray for local anesthetics. He pointed: “See? Her abomasum is right there. That’s huge!” The abomasum was hugely distended with gas and floating right under the surgical incision. Dr. Cripi put a needle into it, attached to a long tube, and let a lot of the gas out. He had all the students smell the gas: a sort of sweet smell, much nicer than rumen smell. (The rumen is the largest and possibly most important part of the cow’s complicated four chamber stomach, the part that feed first falls into to ferment.) The farmer declined to take a sniff, and made a face.

Once the abomasum was somewhat deflated, Dr. Cripi tacked it to the body wall with tacking sutures. Then he closed the incision’s lower layers with the biggest needle I have ever seen in my life. Then he showed me how to close the last layer, the skin. I have done my share of small animal skin closures, and this was really different: that cow’s skin was insanely thick and tough. If you’ve sewn leather, you know what it’s like. I had to really put my back into it to get the needle through.

Then we dosed the cow with a liter of intravenous fluids plus dextrose, and a liter of electrolyte solution. I got to hold the fluids up “as high as you can!” If it is going to make your arm tired, it is the student’s job.

Then the cow walked politely back on her truck and went home.

We got in our truck and headed off to our first farm, with Dr. Cripi angsting about how late we were the whole way. En route, we talked about our lives. Some ambulatory vets use the ride as a teaching opportunity (Dr. Mulain); some ride in silence (Dr. Thery); some just want to chat (Drs. Cole and Cripi). Dr. Cripi had a pretty interesting life, it turned out, spending five years just traveling the world before realizing he wanted to work with food animals as a veterinarian.

Farm number one: a herd check. Checking cows in a herd for pregnancy seems to be the bread and butter of the practice. It was a typical concrete floor, feces-covered barn, but with a particularly open design that I really liked, basically just a roof over the cows, no walls. I asked about their plans for winter (this was a brand new structure). They intend to put up some cover then, but nothing permanent. We worked with a fantastic view of rolling Connecticut hills. It was a lovely scene to look at while putting one’s arm up a cow’s butt.

This farm’s staff included a scrawny kid just out of his teenage years who noticed that a female had arrived and immediately took off his shirt. This became even more hilarious when I was told that it was my job to castrate a bull calf and that the kid would help restrain. I later asked Dr. Cripi if the kid took off his shirt every time a female vet student appeared. Dr. Cripi rolled his eyes and said yes.

How to castrate a bull calf: the vet will draw a diagram for you on a paper towel, hand you a scalpel, and send you on your way. I asked if we used lidocaine for analgesia; he said I could if I wanted to. I said yes please. (The debate in use of lidocaine for a local block in castration is that arguably it is more unpleasant to have a needle shoved into multiple spots in your scrotum and have something that burns injected than just to have the stuff ripped off real quick. Personally I think pain meds are mandatory, but even more so if the job is being done by someone who’s never done it before.) I gave the calf lidocaine injections at various locations around his scrotum and waited five minutes for it to take effect.

My experience in castrating dogs and cats was helpful. I cut off the tip of the scrotum, squeezed the testicles out. They are slippery and don’t like to come out, but I had done this before on a smaller scale and knew how to squeeze. Then I grabbed them and pulled until they came off. (The hardest part was getting a grip. In small animal medicine one uses little four by four pads to hold on to them, not your hands.) The kid asked why we didn’t just cut them off. I said that Dr. Cripi hadn’t said, but my guess was that the bleeding would be worse if you cut; ripping provides some hemostasis.

Farm number two. En route, the sun came out. My spirits immediately lifted. It is amazing what a difference some blue sky makes. At this farm we had a sick cow who was two weeks fresh. This means she gave birth two weeks ago and has been being milked for two weeks. The stress of parturition means that many of these fresh cows are at risk for a variety of diseases, like a displaced abomasum such as we’d seen earlier that morning. In this case, she seemed to have some nerve injury from when the baby passed over the obturator nerve along the pelvis. We prescribed rest, TLC, and anti-inflammatories (banamine is what you give to cows).

Farm number three. Another hobby farm, but a somewhat bigger one. This farmer had quit her previous job to just be a cow farmer, and her husband’s income was presumably supporting the operation. The cows were out on grass in a truly lovely setting (we drove over a little covered bridge across what I have to describe as a sparkling brook on the way in). The cows were spotlessly clean. Normally you sort of hesitate to pet them because of all the manure all over them (at least until you have manure on your hands, which inevitably happens). These cows were so clean that I actually sniffed one and discovered that natural (manure free) cow smell is a lot like horse smell. The farmer had put the sick cow into a holding area, which had a concrete floor which was also spotlessly clean. No huge masses of spider webs! No dead birds in the rafters! Crazy! The farmer actually hovered with a bucket to catch the urine when the cows peed, which is farther than I would go in her place, but I really did appreciate the cleanliness. As Dr. Cripi pointed out, these cows were basically pets.

This cow had a left displaced abomasum (same problem as the first patient of the day, different side). LDAs are actually a lot more common than RDAs, which is too bad, as you still have to cut on the right side of the cow (the rumen covers everything on the left side) and as you then have to reach across the inside of the cow to get to the abomasum on the other side, it becomes quite a process. This cow was dry (no longer being milked) and due to freshen (give birth) in a few weeks. Dr. Cripi was amazed that she had an LDA. Dry cows almost never get displaced abomasums; it is a disease of fresh cows. Cows out on grass also almost never get this disease. This particular cow also turned out to have pneumonia, so maybe the stress of that had caused the displacement. Weird.

So, same surgery, except that Dr. Cripi had to reach through the cow this time instead of having the abomasum pop right up under his incision. I did not get to close, as I had inadvertently contaminated myself on the cow’s side while trying to prevent the drape from falling off of her.

Last farm of the day: again, a horse owner. Her horse needed his yearly vaccines. He was 31 years old! He was a super nice horse. Dr. Cripi sat down and handed me the vaccine bottles. I drew them up and injected them into the horse’s neck. He never flinched. Old patients can be the easiest ones to handle.

Friday, September 9, 2011

Day 2 of my Ambulatory rotation. Still raining. I rode with Dr. Cole and one other student.

First we visited a lovely hobby farm, meaning a farm which is not expected to bring in enough revenue to support the owner. These owners bred and showed registered Ayershire cows, and sold their milk as a sideline. They had full time jobs elsewhere. This was a tiny barn, milking around just 20 cows, very clean relative to other barns (I never had to wade through an ankle-deep sea of manure, which is more than I can say for some other farms we visited), and the cows seemed very healthy.

Next we did a herd check at another, larger farm. More rectal palpations. I complained to Dr. Cole that I had no idea what I was doing when I put my arm in there. He walked us through a guide of how we should approach the situation, complete with an actual size model of a cow uterus. Awesome! Here are his instructions, because I know you are desperate to know:

First you feel for the vaginal canal and/or the cervix. These are fairly caudal (the direction of the cow away from the head) so don’t overshoot them.

Follow the cervix cranially (forward). Behold the body of the uterus.

The body of the uterus may have fallen off the floor of the pelvis into the abdomen. If so, grab it and pull it back up onto the pelvis so you can handle it.

Follow the uterus to the right. Ovary! Not necessarily round. It may be more elongated. Often golf ball sized.

Do the same on the left.

I got to where I could find the vaginal canal and/or cervix and the uterine body pretty reliably. I am still bad at finding the actual uterine horns. If I hunt around long enough I can blunder into the right ovary, but it is awkward to reach to the left, so I have yet to find the left ovary. (You palpate with your non-dominant hand so that your dominant hand is free to do things like write down your findings. So I palpate with my left hand. Since you face towards the cow while you’re palpating, reaching to the right is easy and reaching to the left is hard.)

Next stop was another farm for a herd check, 2 rabies vaccines, and 2 health certificates for some calves that were being taken to the fair. We’ve actually done a fair number of health certificates this week. Autumn is town and county fair season, so the kids are all taking their cows out to show them. At this farm I got to see one cow being prepped for the trip by being buzzed down smooth with some clippers.

The last farm was a herd check, 3 calves to dehorn, and 3 lame cows to check on. We tied each lame cow to a post by the head, then lifted the problem foot by means of a complicated rope pulley system that I supposedly learned in my Clinical Skills class but which I certainly could not duplicate on my own. (“Throw a half-hitch here... That’s not a half hitch! Well, do you at least remember how to do a quick release knot?”) The cows would then kick and freak out, so someone had to tail jack them to keep them distracted. Tail jacking means holding the cow’s tail straight up. To do this you have to stand very close to the cow and lean into the tail. She won’t kick you once you’re close, because they kick out to the side, not back. But getting close can be tricky. I learned: get in and tail jack her before they lift her leg and she starts hopping around and kicking. That works much better. (Trim feet down so you can see the problem. Declare the problem to be hairy heel warts. Yes, that’s an actual disease, caused by a species of bacteria. Apply powder antibiotic and bandage the foot. Done.)

Day 2 done. Still cold. Still wet. Starting to feel more like I know what I’m doing.

Thursday, September 8, 2011

The first day of my ambulatory (food animal medicine) rotation, I got horribly lost on the way to the clinic, which is about an hour from my home. I came in late and missed half of the orientation. Ambulatory is so called because its vets go to the clients rather than vice versa. There are eight students on the rotation right now, but we break up into groups of one to three and ride along with individual vets.

Day one, three students, Dr. Mulain.

Farm one: herd check! Lots of rectal palpations to discover the pregnancy status of cows. If not pregnant, they would get an injection of a medication to reboot their reproductive cycle, so that their owner would know when they were going to come back into heat and therefore when to breed them. Dr. Mulain palpated first and we followed after, one student per cow. Mostly I put my arm in and waved it around aimlessly, hoping to randomly encounter a uterus.

We also dehorned some baby calves at this farm, and checked up on a lame cow who had had a claw (half her foot) removed a few weeks ago. Her bandage was removed and the clients were told to clean her foot regularly. We checked another lame cow, trimmed back her foot, and cleaned out a sore on it.

Farm two: a steer had been hit by a car! The barn had been broken into by thieves the night before and the inhabitants had escaped. The steer was covered in road rash, which we cleaned. His tail was mangled, and we amputated it. His biggest problem was a dislocated hip. We provided anti-inflammatories and advice that he was unlikely to be able to live with a dislocated hip, but that there was a small chance it would heal.

This farm also produced a calf who had injured her eye a few days before. The eye was not salvageable. We put the calf under general anesthesia with an injection and laid her down on the barn floor, then removed the eye. It was an odd experience for me, as I had just finished my small animal surgery rotation. The levels of cleanliness vary tremendously between the two rotations, to say the least.

Farm three: a house with two elderly horses in a tiny barn out back. One had been suffering from neurologic disease for years and was now increasingly lame. We cleaned out an abscess on his hoof and put on medication and a bandage. The horse looked like he was minutes from expiring, but the vet told us that he always looked like that and always pulls through.

So ended my first day of ambulatory, cold and wet. I trust that the weather will improve, though. September in New England is always lovely.

Saturday, August 20, 2011

Recently, an owner refused to let me perform a physical examination on his dog. That was for the vet to do. I think he didn’t believe that I had any role in his dog’s care, and thought I was just along to watch and learn from the vets. Not so! (The examples below are all things that have happened to me and owners of my patients.)

At a teaching facility, your vet student is your pet’s primary caretaker. She is the one who knows your pet the best. She has to present your pet’s clinical history to the residents and faculty every day, follow up on test results, and make sure nothing is overlooked or forgotten about. She is also the one who notices things like what kind of food your dog likes best, whether he likes to be taken a little farther from the hospital than usual so that he can pee on grass instead of stones, and takes time out of her day to cuddle with him if he looks sad. (To be fair, the techs also handle a lot of this sort of thing.)

Your vet student is the one who lets you know how your dog is doing. She will call you at least once a day to tell you if your dog is stressed or not, and give you the updates that really matter, like “today he barked at me while I was writing up paperwork until I took him out of his cage to cuddle with him.” Sometimes hearing stories that remind you that your dog still has the same personality as he does at home is just as important emotionally as getting the complicated medical updates from the doctor.

Your vet student is your liaison to the doctor. The doctor is a specialist who is very, very busy. He will give you lots of information, and you will try to digest it all, but you will have trouble really absorbing it. Your vet student is the one who will take the time to answer all your questions in terms you can understand. She will also be understanding if you are anxious about your pet and will tell you that you are going to do fine taking care of him once he comes home. Maybe she will even help you pad the blankets in your car just right before you settle him in to transport him.

Your vet student is required to be a generalist. The faculty and residents on your pet’s case are all specialists. Sometimes having a generalist around is important. If your dog is in for orthopedic surgery, the specialists may be so focused on your dog’s joint problems that they may not think to perform a rectal exam on him, even though he is a ten year old intact male at risk for all sorts of cancer. But your vet student will remember. (The dog had a mass.)

On a recent shelter medicine externship, I was spaying a kitten. On this externship, you get to spay several animals every day, and I had gotten comfortable enough at it that I was hoping to get through the entire surgery without ever asking for help. To understand what I was doing, you have to understand a little about cat uteruses. Human uteruses are one big sac, probably because we tend to have just one or two babies at a time. Cat uteruses are divided into two horns, each with an ovary at the top, and the horn and ovary are attached to the body wall to hold the whole contraption in place. The horns of pregnant cats fill up with kittens, all in a row.The two horns come together at their base, where there is a little uterine body, which connects to the cervix and from there to the vagina and the outside world. To spay a cat, you cut each ovary and horn away from the body wall. Then you have loose horns, and a base which still attaches to the cervix and vagina and outside world. You cut across the base, and then you have a free uterus and a spayed cat.

So I opened this kitten up, careful to make my incision very short. Longer incisions make visualizing your work easier, but obviously are more painful for the animal, and I had just been criticized on my previous spay for making too long an incision. I used my spay hook to fish around in the abdomen, found the first uterine horn and ovary, pulled them out, and cut them away from the body wall. I traced the now-free uterine horn back to the uterine body.

Finding the first horn is hard: you dip in with the spay hook and blindly bring stuff up, mostly intestines, which you have to repeatedly shove back in until you finally get the organ you’re looking for. Finding the second horn is easy: you follow the first one back to the uterine body, and then pull the second horn out where they both split off from the base. Except in this case, I couldn’t find it. I pulled on the uterine body, which should have made the horn pop out, but no go. I pulled harder. The uterine body started to fray. Oops! I didn’t want it to break before I could find the second horn. I had a moment of indecision: I really, really wanted to get through this whole operation without asking a vet for help. And the problem was probably just that I had made the incision too small. But I had seen too many episodes of ER in which overconfident students got into trouble in exactly this way, and if the uterus split apart before I had a chance to put a suture around it to stop any bleeding, that could potentially be dangerous for the kitten. So I called over Dr. Vine.

Dr. Vine assured me that my incision was an excellent size, and pulled on the uterine body some more. It promptly broke off in her hand. (I congratulated myself on setting her up for dealing with that situation instead of getting myself into it.) It was not a big deal, in the end: she hunted down the stump and we put some suture around it. And she said: This cat only has one uterine horn. It only has half a uterus.

Freakish! And cool. And do you know what? Cats that only have one uterine horn always, 100% of the time, have two ovaries. So if you don’t go hunt down that second ovary, they will still have heat cycles. (They won’t get pregnant, of course, but cats in heat are no fun to have around.) Dr. Vine asked me where I thought the ovary might be. I suggested, in my usual precise fashion, “Somewhere sort of near the... kidney?”

It turns out that that was exactly the answer she was looking for, because, even weirder: about 50% of cats who have only one uterine horn also have only one kidney. And this cat was one of them.

In the end, we found the ovary, just sitting there not really near anything, and we removed it. One more missing uterus for my collection, or half of one. These things come in threes, right? Does this experience count as my third missing uterus, or just two and a half?

Friday, August 5, 2011

I was really surprised at how interesting I found my ophthalmology rotation. Two weeks of eyeballs should have been mostly boring and creepy, right? But it turned out to be rife with my favorite kind of veterinary ethical issue: how we breed dogs.

Take the several bulldogs we saw who had so many facial wrinkles that their skin was folded over their eyes and rubbed against their eyeballs. (They also had yeast infections in the depths of their wrinkles, but that was a problem for a different department.) These dogs required surgical intervention to cut off the worst of the wrinkles. If they did not receive the surgery, they would be extremely uncomfortable (they all came in with red, squinty eyes), and would eventually get corneal ulcers which would proceed to infections and possible removal of the eye in question.

We also saw a raft of brachycephalic (flat-faced) dogs whose faces were so flattened that their eyes bulged out. Some of them could not completely close their eyelids. Their eyes were at risk for damage just due to being so out there in the world and unprotected. In the opinion of the ophthalmologists, pug owners all need to be given special eye care instructions when they acquire their new dog.

I asked the owner of one of the dogs that required surgery about where he had gotten the dog. He replied that the dog came from a breeder. I suggested that he get in touch with the breeder to let her know about the necessary surgery, so that she could use that information to help her choose wisely which dogs to breed in the future, and try to avoid producing more puppies with the problem. He replied in surprise, “I thought this was just a breed-related problem.”

Yes, these are breed-related problems. But breed-related isn’t synonymous with inevitable. It doesn’t mean we can’t try to avoid them as we create more dogs of that breed. Veterinarians can and should be more clear with their clients about this. They don’t have to be confrontational to do it! They don’t have to imply that the client made a mistake by purchasing the dog. They can instead look to the future: here’s what we can do to make the breed better.

Sunday, July 31, 2011

Everyone loves reading about the Siberian fox experiment because domesticated silver foxes are so damn cute. There’s something deeply appealing about the idea of a cuddly fox. And the experiment raised some interesting questions about domestication. Could domestication really happen in just eight generations? (Apparently.) Domestication must just affect the brain and not the rest of the body, right? (Apparently not – domesticated foxes can have characteristic coat color changes, floppy ears, and curly tails, similar to morphologic differences between dogs and wolves.) But a research population of domesticated foxes hasn’t been maintained since the sixties just because they are cute. We’re still learning things from them. Like what? Get ready for some well-aged papers; a lot of this work was done back in the eighties.

Hormone and neurotransmitter soup

We use the hormone cortisol as a marker of stress: if you have more cortisol in your blood, you’re probably more stressed. It turns out, perhaps not surprisingly, that domesticated foxes have lower basal levels of cortisol than their unselected counterparts (Oskina, 1992). Their cortisol levels also don’t go up as high during a stressful experience as do the cortisol levels of unselected foxes (Harri, 2003). Personally, I think cortisol is going to play a key role in the mechanism of why domesticated animals are less flighty than wild ones. Cortisol levels influence the production of adrenaline: if you have more cortisol in your system, you are liable to make more adrenaline (Kvetnansky, 2009). If you have more adrenaline in your system, you are going to react more strongly to scary stimuli – in other words, your flight distance is going to increase. (Quick review – domesticated foxes were bred by selection for decreased flight distance from humans.) My friends and I noticed during our highly stressful first year of veterinary school, when our cortisol levels were certainly high, that were were inexplicably jumpy. One friend reported that she was so startled by the noise of a dropped glass that she actually screamed.

As for the ever-popular serotonin, the “happy hormone,” domesticated foxes have more of it in their midbrains and hypothalamuses (Popova, 1991). Yes, the same hypothalamus that is the beginning of the hypothalamic-pituitary-adrenal axis, which ends in the release of cortisol. Oh, and which is inhibited by having more cortisol already in the system, in a negative feedback loop.

There is nothing cuter than a baby domesticated fox

Wolf cubs have a much shorter socialization window than dog puppies, and this might be part of why it is so difficult to socialize a wolf cub to humans. It turns out that unselected fox kits have a shorter socialization window than domesticated fox kits, too. Prime socialization time in both lines seems to start around 30-35 days, when the kits can see and hear and are mobile enough to explore their surroundings. Like most very young animals, fox kits of this age aren’t as fearful as their adult counterparts; they have a chance to learn what is dangerous and what is not in their particular environment. A longer socialization window gives you more chances to learn that a variety of beings are not dangerous to you, but in the wild it also gives you a greater chance of getting eaten by something that is dangerous to you when you wander up to say hello to it.

Domesticated fox kits start showing fear of new objects after age 60-65 days. Unselected kits, on the other hand, start fearing novel things at day 40-45 (Belyaev, 1985). We don’t know what exactly causes this difference in a preprogrammed socialization window, but it’s very helpful to have these populations as we look for the cause.

An even lower level of programming

In recent years, researchers have had new tools to use in exploring the mechanisms of domestication in foxes, especially since the canine genome was sequenced. Comparing gene expression in the wolf and the dog is problematic, because they necessarily live in such different environments. Comparing gene expression in two populations of foxes raised in identical conditions is potentially much more fruitful. This research is in the early days. But as we learn more about the canine genome I think we’ll start finding some really interesting differences between the lines of domesticated and unselected foxes. My personal belief is that we’ll find subtle differences – maybe, rather than differences in actual genes, we’ll see changes in promoter sequences, which cause significant genes to be up or down regulated.

We’ve learned a lot from the Russian domesticated foxes so far, but we have a long way yet to go. We still have no real idea exactly what is at the root of the difference between a domesticated and undomesticated animal. Does the change in development affect cortisol and serotonin levels, or vice versa? Does just a single genetic modification cause all the physiologic changes we see? Or are we looking for a set of modifications? Hopefully the new genomic tools we’re developing will allow us to get to the bottom of the mystery.

About the Dog Zombie

Jessica Perry Hekman, DVM, PhD is fascinated by dog brains. She is a postdoctoral associate at the Broad Institute of MIT and Harvard, where she studies the genetics of dog behavior. Her interests include the stress response in mammals, canine behavior, canine domestication, shelter medicine, animal welfare, and open access publishing. You may learn more about Jessica at www.dogzombie.com, or email her at jph at dogzombie dot com. All opinions expressed here are her own.

For the animal shall not be measured by man… They are not brethren, they are not underlings: they are other nations, caught with ourselves in the net of life and time, fellow prisoners of the splendor and travail of the earth. (Henry Beston)